Number called for supporters joining team (4,6)

'number called' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.

'supporters joining team' is the wordplay.
'supporters' becomes 'legs'.
'joining' means one lot of letters go next to another.
'team' becomes 'eleven' (eleven is a kind of team).
'legs'+'eleven'='LEGS ELEVEN'

'for' is the link.

Can you help me to learn more?